A carburetor generally blends air and fuel for combustion within an internal combustion engine. Typically, a carburetor comprises an open pipe, or throat, through which air is drawn into an intake of an internal combustion engine, and a throttle valve to control the airflow through the carburetor. The throttle valve typically is of the butterfly variety, comprising a rotatable disk within the throat of the carburetor and in operative communication with a throttle control of the engine. The butterfly valve may be rotated within the throat between a first extremal position wherein the valve obstructs a large portion of the airflow into the intake and a second extremal position wherein the butterfly valve offers very little resistance to incoming air, thereby allowing a maximal airflow into the intake.
A Venturi positioned above the butterfly valve generally comprises a narrow section within the throat wherein airflow through the carburetor increases in speed. Fuel is introduced into the airflow through small holes at the narrowest part of the Venturi. Fuel flow into the airflow is adjusted by way of precisely calibrated orifices, referred to as jets, positioned within a fuel reservoir, called a fuel bowl. During operation, engine power and speed is controlled by way of the butterfly valve, whereby positioning the butterfly valve at the first extremal position limits the quantity of air and fuel introduced into the engine, and positioning the throttle valve at the second extremal position allows a maximal quantity of air and fuel into the engine.
The fuel bowl typically comprises a float chamber which maintains a quantity of fuel at near-atmospheric pressure, ready for use. The float chamber is constantly replenished by way of a fuel pump which supplies fuel through an inlet valve. An advantageous fuel level is maintained within the fuel bowl by way of a float controlling the inlet valve. As fuel is drawn into the engine through the Venturi, the quantity of fuel in the float chamber decreases, causing the float to drop within float chamber, thereby opening the inlet valve and allowing fuel to enter the float chamber. As the fuel level rises, the float rises within the float chamber until the inlet valve is closed. Generally, ventilation tubes are used to allow atmospheric pressure to be maintained in the float chamber as the fuel level changes. The ventilation tubes typically extend from the float chamber into the carburetor throat.
One drawback to conventional fuel bowls is that under some circumstances, such as during acceleration, fuel may slosh out of the float chamber and into the carburetor throat, thereby giving rise to engine performance problems. Another drawback is that conventional inlet valves are position at the top of the float chamber, thereby allowing fuel to enter at the top of the fuel bowl. When fuel enters at the top of the fuel bowl, the fuel may become aerated which fills the fuel bowl with fuel having a reduced density, thereby reducing engine performance. Still another drawback to conventional fuel bowls is that they are designed so as to have an airspace above the fuel level within the float chamber, which allows the fuel to slosh around within the float chamber, thus leading to aeration of the fuel within the fuel bowl. What is needed, therefore, is a fuel bowl which prevents aeration of the fuel within the float chamber.